Self-stabilizing force distributing apparatus

ABSTRACT

A freely positionable force transfer device for applying forces at selected directions and magnitudes to reform and straighten structures. The device is operative to receive a force producing power strut and reactive force members to direct the forces of each through a common axis to minimize internal moments and ensure stable operation in a plurality of geometrical arrangements within the operational range of the device.

United States Patent Hunnicutt 1 June 6, 197 2 54] SELF-STABILIZING FORCE 1,676,263 7/1928 Hawkins ..72/7o5 DISTRIBUTING APPARATUS 1,785,923 12/1930 Wade ..72/705 [72] Inventor: Wayne E. Hunnicutt, Big Bend, Wis. p Emminer Mi|ton S. Mehr [73] Assignee: Applied Power Industries, Inc., Milwau- A'wmey"petherbfidgei ONem Lindgren kee, Wis.

[22] Filed: Feb. 25, 1970 [57] ABSTRACT [2]] Appl' 13928 A freely positionable force transfer device for applying forces at selected directions and magnitudes to reform and straighten [52] U.S. CI ..72/302, 72/705 structures. e ice is operat ve to rece ve a force produc- [51] Int. Cl ..B21d 1/12 ing power strut and reactive force members to direct the [58] Field of Search ..72/705, 302; 254/93 forces of each through a common axis to minimize internal moments and ensure stable operation in a plurality of geomet- [56] References Cited rical arrangements within the operational range of the device.

UNITED STATES PATENTS 10 Claims, 4 Drawing Figures 3,014,696 12 1961 Trutt ..254/93 PATENTEHJUH 6 m2 3 6 6 7. 275

SHEET 1 [IF 2 INVENTOR,

WAYNE E. HUNNICUTT ATTORNEYS.

PATENTEDJUN 6l972 3,667,275

.sumzorz INVENTOR.

WAYNE E. HUNNICUTT ATTORNEYS.

SELF-STABILIZING FORCE DISTRIBUTING APPARATUS BACKGROUND OF THE INVENTION This invention relates to and is adapted to be used with apparatus for reforming and straightening structural members such as disclosed in co-pending U. S. Pat. application, Ser. No. 744,824 filed on July 15, 1968 now US. Pat. No. 3,590,623 in the name of Wayne E. Hunnicutt et al., reference is made thereto for the disclosure therein.

Application Ser. No. 744,824 discloses in general, a platform comprising a grid pattern of channels imbedded in a concrete slab upon which, for example, a wrecked automobile is placed. Through various geometrical arrangements of force applying means such as power driven rams acting upon rigid struts, together with flexible force reactive elements such as chains, forces in a plurality of directions and magnitudes can be obtained.

The instant device is used in cooperation with the apparatus disclosed in the above identified co-pending application such that an axially loadable rigid compression strut and a force producing power strut anchored to the platform when coupled together by the instant force transfer device form a self-stabilizing compressive force transfer device.

It is, therefore, an object of the invention to self-stabilize a force transferring and distributing device.

Still another object of the invention is to distribute the forces produced by a power strut to each of a plurality of reactive members through selected geometrical arrangements.

A further object of the foregoing is to stabilize a rigid axially loaded reactive member to maintain its position in the same plane as the load producing force.

Another object of the invention is to direct each of the applied forces through a common axis proximate each other to minimize internal moments.

A still further object of the invention is to direct the applied forces of the strut and members through a common axis in a plurality of operational geometric arrangements to maintain each arrangement stable.

Another object of the invention is to maintain a self-stabilizing device by utilizing a flexible reactive member anchored to the platform fonning a sling which pivots about the common axis of force intersection.

A more specific object of the foregoing is to connect the flexible reactive element below the common axis of the compression and power struts to obtain self-stabilization.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the device in a typically operating arrangement on the partially shown platform;

FIG. 2 is a side view of the device substantially as shown in FIG. 1;

FIG. 3 is a view taken substantially at line 3-3 of FIG. 2; and

FIG. 4 is a view taken substantially at line 44 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown a platform comprising slotted channels 12 imbedded in a concrete slab 14 to form a grid pattern of anchoring positions for apparatus used in reforming and straightening structures.

The instant invention generally designated is shown in a typical operating arrangement above the platform 10 with a flexible reactive member, chain 16, engaging a portion of the device 20 to form a sling having legs 17 and 18. Each of the legs is anchored to the channels at spaced locations by means of a clamp assembly 19 positionable in an infinite number of locations along the grid pattern of the channels 12.

The platform 10, channels 12 and clamp assemblies 19 are fully disclosed in aforementioned co-pending U.S. Pat. application, Ser. No. 744,824 and reference is made thereto for details of such a system.

An extensible power strut, shown as hydraulic ram connected to a hydraulic power source (not shown) by a hose 41, is pivotally retained at its lower end 42 in one of the clamp assemblies 19 anchored to the platform 10 as shown. The ram 40 has an extension shaft 43 extending upwardly to the device 20 forming a tripod with legs 17 and 18 of the chain 16. The device 20 forms the apex of the tripod and has extending therefrom a rigid strut which is axially loaded by the ram 40.

The power strut 40 may be of any suitable known type preferably such as porto-power hydraulic ram manufactured by Blackhawk Manufacturing Company of Milwaukee, Wisconsin. However, such an extensible power strut could be electrical, air or manually powered.

As shown in FIGS. 2, 3 and 4, the device 20 comprises a knuckle and clevis designated 21 and 22, respectively, and a chain yoke 23 pivotally connected by a common retaining pin 24. As best seen in FIG. 4, the knuckle 21 includes a tongue portion 29 extending from one end of a body 30. The body 30 has an internal bore 31 for receiving struts such as the rigid strut 45 shown in FIG. 1. The tongue portion has a centrally disposed hole 28 slightly larger than that of the pin 24 to receive the pin and allow rotational movement of the knuckle assembly 21 about the pin 24.

The clevis 22 includes a pair of wall arms 32 and 33, respectively, defining a space 34 therebetween for loosely receiving the tongue 29 of the knuckle 21. The wall members 32 and 33 merge into a body portion 35 which has an internal bore 36 for receiving struts such as the extension shaft 43 shown in FIG. 1. Each of the arms 32 and 33 have axially aligned holes 37 and 38, respectively, slightly larger than that of the pin 24 to receive the pin and permit rotational movement thereabout.

The chain yoke 23 comprises a pair of upwardly extending arms and 51 each terminating in a hub portions 52 and 53, respectively. The arm structures 50 and 51 merge at their lower ends to form a bight portion 54 having a slot 55 therein for securing the chain 16 against sliding through the yoke 23 during operation. The arms 50 and 51 have spaces 56' and 57 to permit maximum angular positioning between the knuckle 21 and clevis 22 (see FIG. 2) and to facilitate threading the chain 16 through the arm structures (50, 51) during set up.

The hub portions 52 and'53 each have axially aligned holes 58 and 57 respectively, providing a snug fit for the pin 24. A set screw 60 mounted in a threaded bore 61 engages the pin 24 to prevent lateral and rotational movement. As best seen in the FIG. 4, when the knuckle 21, clevis 22 and chain yoke 23 are assembled, the holes 58, 37, 28, 38, 57 are aligned and the pin 24 defines a principal axis X-X about which the knuckle 21, clevis 22 and chain yoke 23 are rotatable relative to each other.

Referring again to FIG. 1, a typical operational arrangement is shown illustrating the device 20 transmitting a compressive axial load to rigid strut 45 for application to a structural member of a vehicle. The extensible ram 40 provides a force FC designated by an arrow typically indicating a force and direction of application.

The chain 16 and rigid strut 45 act as reactive members in this arrangement and transmit reactive forces FY and FK respectively. It can be seen in FIGS. 2 and 3 that all three forces (FC, FY and FK) pass through the axis X-X.

As best seen in FIG. 4, the force FK is applied at substantially the center of the pin 24 and reacts against the force FC produced by the ram 40. This force FC is represented as a pair of essentially equal forces FCl and FC2 carried by the clevis arms 32 and 33, respectively, to the pin 24. Since the arms (32 and 33) are symmetrically disposed with respect to the tongue 29, there are no significant couples or moments produced in the pin 24 by forces FCl and FC2. The vertical components of force in the arrangement are counteracted by chain 16. As shown, chain yoke 23 is restrained from upward movement by the chain 16 anchored to the platform 10. The reactive forces of legs 17 and 18 are designated FF! and FP2 respectively. These forces (FPl and FP2) equal the downward force FY.

The force FY acts upon the pin 24 at the hubs 52 and 53 as two substantially equal forces FYI and FY2 respectively. Here again, as with the clevis 22, the'hub 52 and 53 of the yoke are symmetrically disposed relative to both the clevis 22 and the tongue 29. Because of this symmetry the essentially equal forces FYI and FY2 are applied to the pin 24 in a symmetrical relation to the other forces (FK, FCl and FC2) acting on the pin. This symmetrical relation cancels couples or moments at the pin 24.

Another important feature of the clevis pin disposition of the disclosed structuresis that as the forces (FK, FCl, FC2, FYI and FY2) act upon the pin 24, they pass through the axis X-X at angles substantially normal to that axis defining a plane in which forces act. When the legs 17 and 18 of chain 16 are equal in length, as shown, this plane will be substantially normal to the platform regardless of the angular relation of I the reactive and force producing struts. However, the apparatus will maintain. a stable configuration whenever the force plane lies between legs 17 and 18.

Furthermore, as the structural frame member (see FIG. 1) deforms in response to the force of strut 45, the device 20 moves in an arcuatepath defined by the legs 17 and 18 of chain 16 and their positional relationship on the platform 10, As shown, the angular forces FPl and FPZ are exerted at a point which is always below the axis X-X. This relationship, together with the forces acting in substantially the same plane, assure the operational stability of the device in numerous angular arrangements.

The self-stabilizing apparatus 20 is structured so that the forces distributed therethrough cancel all significant internal moments or couples. It should also be noted that the forces at the device 20 lie substantially within a plane normal to the platform 10 in the usual geometrical arrangement. This force distribution, along with the engaging position of chain 16, maintains the stability of the device 20 in moving through an arcuate path during operation.

It will be appreciated that the embodiment of the invention chosen for the purposes of illustration and description herein is that preferred based upon requirements for achieving the objects of the invention and developing the utility thereof in the most desirable manner, due regard being had to existing factors of economy, simplicity of design and construction, production methods and the improvements sought to be effected. It will be understood, that the particular structure and functional aspect emphasized herein are not intended to exclude but rather to suggest such other modifications and adaptations as fall within the spirit and scope of the invention as hereinbefore disclosed.

1 claim:

l. A force distributing device selectively positionable to direct force producing power struts and reactive elements in a plurality of statically stable interacting relationships comprismg a force producing power strut receiving means having a clevis formed on an end thereof,

a first reactive element receiving means having a portion pivotally connected within the clevis of said strut receiving means to transmit reactive forces applied thereto, and

a second reactive element receiving means having a yoke formed on an end thereof and pivotally connected about the clevis of said first reactive element receiving means such that all of said receiving means pivot relative to each other about a force intersecting axis whereat each of said receiving means apply their respective forces at an angle substantially normal thereto.

2. The apparatus of claim 1 wherein said yoke includes a bight portion for receiving a downward stabilizing reactive load at a point below said force intersecting axis.

3. The invention as recited in claim 2 wherein said stabilizing reactive load comprises chain sling secured to retaining means at an opposite end.

4. A force distributing device for selectively positioning force transmitting elements in a plurality of statically stable relationships above a platform comprisin a plurality of rigid pivotally connected interacting members for applying forces to an object,

flexible reactive means pivotally connected to-said plurality of rigid pivotally connected interacting members applying a reactive force beneath the pivotable connection thereof for constraining the movement of said members in an arcuate path during application of force to an object, and

each of said plurality of rigid members and said flexible means being operatively connected such that the forces transmitted by each intersect a common axis cancelling moment producing forces.

5. The apparatus of claim 4 wherein one of said rigid pivotally connected interacting members has a free end for applying a compressive force to an object. 7

6. The apparatus of claim 4 wherein said flexible reactive means is pivotally connected to said plurality of rigid members co-axially with the pivotable connection between said plurality of rigid members.

7. An apparatus for reforming and straightening vehicles comprising force producing struts and reactive elements anchorable to a vehicle supporting platform in a plurality of geometrical arrangements comprising a plurality of pivotally connected force transmitting struts for applying a compressive force to a vehicle in a direction parallel to the axis of one of said struts, and

force reactive means secured to a platform upon which a vehicle is supported and pivotally connected to said plurality of force transmitting struts to distribute the forces transmitted through a common axis lying in a plane substantially normal to the compressive force applied to the vehicle thereby maintaining a stable force applying configuration.

8. The apparatus of claim 7 wherein said force reactive means comprises a flexible member secured at its ends to said vehicle supporting platform and pivotally connected to said plurality of force transmitting struts between said ends.

9. The apparatus of claim 8 wherein said flexible member is pivotally connected to said plurality of force transmitting struts by means of a yoke member having a pivotal axis common with the axis of the pivotal connection of said force transmitting struts.

10. The apparatus of claim 7 wherein said force reactive means is pivotally connected to said plurality of pivotally connected force transmitting struts along a common axis. 

1. A force distributing device selectively positionable to direct force producing power struts and reactive elements in a plurality of statically stable interacting relationships comprising a force producing power strut receiving means having a clevis formed on an end thereof, a firSt reactive element receiving means having a portion pivotally connected within the clevis of said strut receiving means to transmit reactive forces applied thereto, and a second reactive element receiving means having a yoke formed on an end thereof and pivotally connected about the clevis of said first reactive element receiving means such that all of said receiving means pivot relative to each other about a force intersecting axis whereat each of said receiving means apply their respective forces at an angle substantially normal thereto.
 2. The apparatus of claim 1 wherein said yoke includes a bight portion for receiving a downward stabilizing reactive load at a point below said force intersecting axis.
 3. The invention as recited in claim 2 wherein said stabilizing reactive load comprises chain sling secured to retaining means at an opposite end.
 4. A force distributing device for selectively positioning force transmitting elements in a plurality of statically stable relationships above a platform comprising a plurality of rigid pivotally connected interacting members for applying forces to an object, flexible reactive means pivotally connected to said plurality of rigid pivotally connected interacting members applying a reactive force beneath the pivotable connection thereof for constraining the movement of said members in an arcuate path during application of force to an object, and each of said plurality of rigid members and said flexible means being operatively connected such that the forces transmitted by each intersect a common axis cancelling moment producing forces.
 5. The apparatus of claim 4 wherein one of said rigid pivotally connected interacting members has a free end for applying a compressive force to an object.
 6. The apparatus of claim 4 wherein said flexible reactive means is pivotally connected to said plurality of rigid members co-axially with the pivotable connection between said plurality of rigid members.
 7. An apparatus for reforming and straightening vehicles comprising force producing struts and reactive elements anchorable to a vehicle supporting platform in a plurality of geometrical arrangements comprising a plurality of pivotally connected force transmitting struts for applying a compressive force to a vehicle in a direction parallel to the axis of one of said struts, and force reactive means secured to a platform upon which a vehicle is supported and pivotally connected to said plurality of force transmitting struts to distribute the forces transmitted through a common axis lying in a plane substantially normal to the compressive force applied to the vehicle thereby maintaining a stable force applying configuration.
 8. The apparatus of claim 7 wherein said force reactive means comprises a flexible member secured at its ends to said vehicle supporting platform and pivotally connected to said plurality of force transmitting struts between said ends.
 9. The apparatus of claim 8 wherein said flexible member is pivotally connected to said plurality of force transmitting struts by means of a yoke member having a pivotal axis common with the axis of the pivotal connection of said force transmitting struts.
 10. The apparatus of claim 7 wherein said force reactive means is pivotally connected to said plurality of pivotally connected force transmitting struts along a common axis. 